Sharp EL-5250, EL-5230 RANGEab, Calculation accuracy, Changing the range of expected values

Appendix

Calculation accuracy

•The calculator solves an equation by comparing the values of the left- hand and right-hand sides of the equation through 14-digit internal operations. If the value of the left-hand side is sufficiently close to agreeing with that of the right-hand side the calculator may present one of the ‘approximate’ values as a solution — even though it is not the true solution.

•The calculator will also stop trying to solve an ‘approximate’ solution either when it has performed more than 50 iterations using each initial expected value or when it has obtained an ‘approximate’ solution that is the same (to 10-digit accuracy) twice in succession.

Changing the range of expected values

After entering your equation by pressing I 5, press @ J to adjust the range of expected values. The calculator will then prompt you for a range of expected values (between –1 ⋅ 1099 and +1 ⋅ 1099) to be used in the calculation.

RANGE:a<b
a=	–1.
b=	1.

a:Lower limit

b:Upper limit

•The range of expected values returns to its default setting (–1 ⋅ 1010 to +1 ⋅ 1010) when the current equation is cleared or the mode is changed.

After entering the lower and upper limits (a and b) of the range of expected values, press j to return to the previous display.

•The best solution can be found by defining the lower or upper limit (a or b) or initial value close to the expected solution.

•Having done this, press @ h several times to generate slightly different solutions. You can judge which of these is the best by comparing the values displayed for the left-hand and right-hand sides of the equation.

122